1. Field of the Invention
The present invention relates to an image forming apparatus such as an electrophotographic or electrostatic copying apparatus or a laser beam printer, and more particularly to an image forming apparatus adapted to form an image on a recording material supported on a recording material support member.
2. Related Background Art
It is already known, in the field of image forming apparatus for forming a full-color image, to support a recording material such as paper on a recording material support member such as a dielectric sheet and to form an image on such recording material. Such image formation can be achieved by transferring an image, formed on an image bearing member such as a photosensitive member, by means of a transfer charger positioned at the back of the recording material support member.
It is also known, for electrostatically attracting the recording material to the recording material support member, to provide a corona charger and a roller electrode as a counter electrode, across said recording material support member. It is also proposed to provide a charging brush for attraction, instead of said corona charger.
In such attraction charging means, as shown in FIG. 2, the center of charging of a charging brush 105c coincides with that of an attraction roller 105g in mutually opposed manner, and is located at the center of the contact area of said charging brush 105c or attraction roller 105g with a recording material support member 105f. However, with such attraction means for electrostatically attracting the recording material to the recording material support member 105f, in which the center of charging of the charging brush 105c coincides with that of the attraction roller 105g in the moving direction of the recording material support member 105f, there has been encountered a drawback that the recording material cannot be stably transported by the recording material support member 105f due to a deficient attractive force. Such drawback becomes particularly conspicuous in case a recording material requiring a large attractive force, such as a cardboard, is transported by the recording material support member 105f for image formation.